Sample 说明

Column/Row 的布局基础
Image的本地图片使用
Modifier 布局控制

package top.zcwfeng.greetingcard

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.Image
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.padding
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import top.zcwfeng.greetingcard.ui.theme.GreetingCardTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            GreetingCardTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colors.background
                ) {

                }
            }
        }
    }
}



@Preview(showBackground = true, showSystemUi = true)
@Composable
fun DefaultPreview() {
    GreetingCardTheme {
        BirthdayGreetingWithImage(message = "Happy Birthdy David", from = " - Weimiao")
    }
}

@Composable
fun BirthdayGreetingWithText(message: String, from: String, modifier: Modifier = Modifier) {
    Column(
        modifier = Modifier.fillMaxSize(),
        verticalArrangement = Arrangement.Top,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        Text(text = message, fontSize = 36.sp, modifier = Modifier.padding(top = 16.dp))
        Text(
            text = from,
            fontSize = 24.sp,
            modifier = Modifier
                .padding(top = 16.dp)
                .align(alignment = Alignment.End)
        )
    }
}

@Composable
fun BirthdayGreetingWithImage(message: String, from: String, modifier: Modifier = Modifier) {
    val image = painterResource(R.drawable.androidparty)
    Image(painter = image, contentDescription = null, contentScale = ContentScale.Crop)
    BirthdayGreetingWithText(message = message, from = from)

}